Effect of hydrostatic pressure on polarization reversal in copolymers of vinylidene fluoride and trifluoroethylene

Polarization reversal in copolymers of vinylidene fluoride (VDF) and trifluoroethylene (TrFE) with intermediate and higher TrFE content is characterized by two polarization current peaks at different electric field intensities. The current peaks at higher and lower field, Eh and El, correspond to polarization and depolarization processes, respectively. The temperature Tl at which El reduced to zero was related to a transition between slightly different phases. The effect of hydrostatic pressure on polarization processes was examined for the copolymers in a low pressure region of 0.1 to 100 MPa. Increasing pressure gave rise to a considerable effect on Eh and El, being similar to that in decreasing temperature. Pressure dependence of the temperature Tl was as large as about 0.3 KMPa-l. This work presents another feature of the polarization processes in these copolymers which are different from those in high VDF content copolymers.